An optical immunosensor for rapid vitellogenin detection in plasma from carp (Cyprinus carpio).

Vitellogenin (vtg) has proven to be a sensitive and simple biomarker for assessing exposure of fish to environmental estrogens. The aim of this work was to develop a rapid, in the order of minutes, screening method for the detection of fish vtg. The surface plasmon resonance technique (Biacore Xtrade mark) was coupled with immunodetection for the determination of fish vtg in plasma and mucus from carp (Cyprinus carpio). Monoclonal anti-vtg antibodies were linked on the sensor surface through chemical cross-linking via a capturing antibody. A simple regeneration process allowed the reuse of the sensor surface. Sensor optimisation was carried out using carp vtg. The developed immunosensor was tested with vtg spiked samples and with plasma and mucus from fish exposed to 17beta-estradiol (E2). Vitellogenin could be detected in the ppm range in buffer as well as in plasma and mucus. Good discrimination between control and exposed samples was obtained. The results were compared with ELISA and a correlation coefficient of R(2)=0.85 (n=9) between the two methods indicated that the immunochemical biosensor could be used for the analysis of vtg in fish plasma samples. The assay time was 20min hence allowing for rapid sample screening.